ORTE_SNAPC(7)

💖 ORTE_SNAPC 💖

okay so bestie, welcome to the ORTE_SNAPC page — that's the Open RTE MCA Snapshot Coordination (SnapC) Framework ✨ it's the whole overview of Open RTE's SnapC framework plus a lil tour of selected modules, and it ships with Open MPI 4.1.6. grab a boba, we're getting into it 🧋

---

🌸 NAME 🌸

ORTE_SNAPC — the Open RTE MCA Snapshot Coordination (SnapC) Framework: a whole overview of Open RTE's SnapC framework, and selected modules. Open MPI 4.1.6 💅

---

✨ DESCRIPTION ✨

so here's the tea 🍵 — Open RTE can coordinate the generation of a global snapshot of a parallel job, built out of like, a million distributed local snapshots. cute right?

and the components in this framework are the ones deciding how to do all of this:

• Initiate the checkpoint of the parallel application 🔥
• Gather together the many distributed local snapshots 🫶
• Provide the user with a global snapshot handle reference that can be used to restart the parallel application ⭐

---

👑 GENERAL PROCESS REQUIREMENTS 👑

ngl, if a process wants to use the Open RTE SnapC components, it has to follow a few programmatic requirements. no skipping, bestie.

• First, the program must call ORTE_INIT early in its execution. This should only be called once, and it is not possible to checkpoint the process without it first having called this function. periodt.
• The program must call ORTE_FINALIZE before termination.
• A user may initiate a checkpoint of a parallel application by using the orte-checkpoint(1) and orte-restart(1) commands 💫

---

🌈 AVAILABLE COMPONENTS 🌈

Open RTE ships with one SnapC component: full.

The following MCA parameters apply to all components:

• snapc_base_verbose — Set the verbosity level for all components. Default is 0, or silent except on error. 🤫

💜 full SnapC Component

The full component gathers together the local snapshots to the disk local to the Head Node Process (HNP) before completing the checkpoint of the process.

🚨 heads up: this component does not currently support replicated HNPs, or timer based gathering of local snapshot data.

This is a 3-tiered hierarchy of coordinators.

The full component has the following MCA parameters:

• snapc_full_priority — The component's priority to use when selecting the most appropriate component for a run.
• snapc_full_verbose — Set the verbosity level for this component. Default is 0, or silent except on error. 🙈

🦋 none SnapC Component

The none component simply selects no SnapC component. All of the SnapC function calls return immediately with ORTE_SUCCESS 💖

This component is the last component to be selected by default. Which means: if another component is available, and the none component was not explicitly requested, then ORTE will attempt to activate all of the available components before falling back to this component. it's giving "backup plan energy" 💀

---

🎀 SEE ALSO 🎀

orte-checkpoint(1), orte-restart(1), opal-checkpoint(1), opal-restart(1), orte_filem(7), opal_crs(7)

---

and that's the whole page, bestie!! 🌟 this iconic little doc is from 4.1.6, dated Sep 30, 2023 — go forth and checkpoint responsibly 🫶💖✨